(a) Field of the Invention
The present invention relates to a laser range finder in which the laser beams pass through the interior of a telescope unit thereof, more particularly an adjusting device adapted to adjust the optical axis of the laser beams and the observation optical axis of the telescope unit so that they overlap.
(b) Description of the Prior Art
The structure of a conventional range finder utilizing laser beams in generally includes cylindrical and juxtaposed laser generator, laser receiver, and a telescope unit. Since the three-cylinder structure will make the range finder bully use thereof is not convenient.
There has been provided a technique in which a laser generator has a part of the laser beam emitted thereby pass through the interior of the lens cylinder of the telescope unit before being projected out of the range finder, whereby the range finder appears like a dual-cylinder construction with a reduced size.
In the dual-cylinder type range finder, the travel path of the invisible laser beams emitted from the range finder to the object to be observed enter the travel path of the interior of the telescope unit along with the visible light beams emitted by the object to be observed, a part of thereof sharing the lens cylinder of the telescope. Therefore, the higher the degree of coincidence of the two travel paths becomes, the greater the accuracy of the results of measurement can be obtained. Hence, during assembly or maintenance of the range finder, a suitable design must be employed to enable the operator to adjust the two paths in an overlapping state.
A primary object of the present invention is to provide an optical axis adjusting device for range finders, in which invisible light beams and a part of the visible light beams can be overlapped.
Another object of the present invention is to provide an optical axis adjusting device for range finders which can alter the size of the included angle between the optical axis of the invisible light beam and the centerline of the telescope unit.
A further object of the present invention is to provide an optical axis adjusting device for range finders which can alter the advancing path of the invisible light beam inside the telescope unit.
In order to achieve the above-mentioned objects, the optical axis adjusting device for range finders according to the present invention includes a range finder that includes a laser emitter, a telescope, and a laser receiver. The laser emitter is provided on the optical axis adjusting device such that a laser beam emitted thereby travels through a predetermined part of the interior of the telescope to project from the range finder. The optical axis adjusting device includes a first coupling portion that is secured on a predetermined part of the range finder, a second coupling portion having a predetermined part secured to the laser emitter with the other part provided on the first coupling portion such that it can reciprocatingly displace along a first direction, and at least one securing element provided between the first and second coupling portions to limit the relative position of the first and second coupling portions.